Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2025
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	*Basis of presentation* The accompanying unaudited consolidated financial statements of Superior included herein have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") and the rules and regulations of the Securities and Exchange Commission (the "SEC"). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to such rules and regulations. Intercompany items have been eliminated in consolidation. These consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, and filed with the SEC. Management believes that the information furnished includes all adjustments of a normal recurring nature that are necessary to fairly present our consolidated financial position, results of operations and cash flows for the periods indicated. The results of operations for any interim period are not necessarily indicative of results to be expected for the full year. The Company refers to the consolidated financial statements collectively as “financial statements,” and individually as “statements of comprehensive income,” “balance sheets,” “statements of shareholders’ equity,” and “statements of cash flows” herein.
Reclassification, Comparability Adjustment [Policy Text Block]	*Reclassifications* The accompanying financial statements for the prior year period contain certain reclassifications. Reclassifications only impact items within our statements of comprehensive income, our statements of shareholders' equity, our statements of cash flows and Note 7 Inventories. These reclassifications did not have an effect on the Company’s consolidated results of operations, financial position or cash flows for the quarter ended June 30, 2025.
New Accounting Pronouncements, Policy [Policy Text Block]	**Recently Issued Accounting Pronouncements Not* Yet Adopted*** In December 2023, the FASB issued ASU 2023-09, "Income Taxes (Topic 740)—Improvements to Income Tax Disclosures". The ASU requires that an entity disclose specific categories in the effective tax rate reconciliation as well as provide additional information for reconciling items that meet a quantitative threshold. Further, the ASU requires certain disclosures of state versus federal income tax expense and taxes paid. The amendments in this ASU are required to be adopted for fiscal years beginning after December 15, 2024, which for the Company is the calendar year beginning January 1, 2025. Early adoption is permitted for annual financial statements that have not yet been issued. The amendments should be applied on a prospective basis although retrospective application is permitted. The adoption of this guidance will not affect the Company’s consolidated results of operations, financial position or cash flows and the Company is currently evaluating the effect the guidance will have on its disclosures. In November 2024, the FASB issued ASU 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses“ The ASU requires the disclosure of additional information about specific categories of costs and expenses in the notes to the consolidated financial statements. This guidance is effective for annual periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. This ASU will likely result in additional disclosures. We are currently evaluating the provisions of this ASU.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2025

Basis of Accounting, Policy [Policy Text Block]

Basis of presentation

The accompanying unaudited consolidated financial statements of Superior included herein have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP") and the rules and regulations of the Securities and Exchange Commission (the "SEC"). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to such rules and regulations. Intercompany items have been eliminated in consolidation. These consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, and filed with the SEC. Management believes that the information furnished includes all adjustments of a normal recurring nature that are necessary to fairly present our consolidated financial position, results of operations and cash flows for the periods indicated. The results of operations for any interim period are not necessarily indicative of results to be expected for the full year.

The Company refers to the consolidated financial statements collectively as “financial statements,” and individually as “statements of comprehensive income,” “balance sheets,” “statements of shareholders’ equity,” and “statements of cash flows” herein.

Reclassification, Comparability Adjustment [Policy Text Block]

Reclassifications

The accompanying financial statements for the prior year period contain certain reclassifications. Reclassifications only impact items within our statements of comprehensive income, our statements of shareholders' equity, our statements of cash flows and Note 7 Inventories. These reclassifications did not have an effect on the Company’s consolidated results of operations, financial position or cash flows for the quarter ended June 30, 2025.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Issued Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU 2023-09, "Income Taxes (Topic 740)—Improvements to Income Tax Disclosures". The ASU requires that an entity disclose specific categories in the effective tax rate reconciliation as well as provide additional information for reconciling items that meet a quantitative threshold. Further, the ASU requires certain disclosures of state versus federal income tax expense and taxes paid. The amendments in this ASU are required to be adopted for fiscal years beginning after December 15, 2024, which for the Company is the calendar year beginning January 1, 2025. Early adoption is permitted for annual financial statements that have not yet been issued. The amendments should be applied on a prospective basis although retrospective application is permitted. The adoption of this guidance will not affect the Company’s consolidated results of operations, financial position or cash flows and the Company is currently evaluating the effect the guidance will have on its disclosures.

In November 2024, the FASB issued ASU 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses“ The ASU requires the disclosure of additional information about specific categories of costs and expenses in the notes to the consolidated financial statements. This guidance is effective for annual periods beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. This ASU will likely result in additional disclosures. We are currently evaluating the provisions of this ASU.